A case was mentioned in which a 22-year-old office worker surnamed Chen (陳) regularly wore her contact lenses for more than 12 hours a day nearly everyday and sometimes slept with her lenses on. She only went to see a doctor when her vision became blurry and her right eye started to hurt and was diagnosed with visual deterioration, leaving her with 0.02 vision — or the ability to see clearly only one arm’s length from her body.

The improper cleaning of her contact lenses also resulted in a pyocyanus corneal ulcer which was only fixed with a corneal transplant this month.

Another case involved a 31-year-old junior-high school teacher who regularly wore contact lens for more than 14 hours everyday. She frequently wore daily disposable contacts during the week, sometimes without even changing the contact lens solution.

After red veins appeared in her eyes and experiencing discomfort even without wearing contact lens, she went to see a doctor and was diagnosed with corneal erosion caused by long-term corneal oxygen deficiency.

Ophthalmological Society of Taiwan Secretary-General Lin Szu-yuan (林思源) said prolonged wearing of contact lenses and improper cleaning can cause eye damage — which often starts with swollen eyes or diminished eyesight. In such situations, if an individual does not seek medical advice from a doctor, the cornea can be damaged by bacteria or fungal infection, potentially causing a corneal ulcer.

According to a 2009 survey on contact lens wearers, more than 50 percent of Taiwanese surveyed who use them said they had fallen asleep with their contact lenses on, and many wear them for as long as 14 hours a day or spend long hours staring at computer screens.